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UNIVERSITY  OF  CALIFORNIA  Agricultural  Experiment  Station 

College  of  Agriculture  E.  J.  Wickson,  Acting  Director 

BERKELEY,  CALIFORNIA 


CIRCULAR  No.  19. 

(April,  1906) 


THE  DISINFECTION  OF  STABLES, 

By   CLARENCE   M.   HARING,   D.V.M. 


By  disinfection  is  meant  the  destruction  of  the  germs  of  infectious 
diseases.  Negligence  in  properly  disinfecting  stalls  and  stables  where 
animals  affected  with  contagious  diseases  have  been,  is  frequently  the 
cause  of  a  reappearance  of  the  disease. 

Many  failures  to  eradicate  tuberculosis  from  dairy  herds  by  the 
repeated  application  of  the  tuberculin  test  and  the  prompt  removal 
of  all  reacting  animals,  are  due  to  the  fact  that  the  stables  were  not 
disinfected.  It  is  a  universally  accepted  fact  that  herds  of  cattle,  when 
kept  closely  together  in  large  stables,  are  the  most  liable  to  be  badly 
infected  with  tuberculosis.  This  is  especially  marked  when  the  stables 
have  been  in  constant  use  for  a  number  of  years.  Under  such  condi- 
tions the  dissemination  of  tuberculosis  is  very  rapid,  and  continues 
after  all  diseased  animals  have  been  removed  and  other  cattle  substi- 
tuted. Since  bovine  tuberculosis  is  so  widely  disseminated,  most  dairies 
in  which  the  tuberculin  test  is  not  frequently  applied  become  infected. 
There  can  be  no  question  but  that  frequent  disinfection  retards  its 
spread,  and  thorough  disinfection  of  the  stable  at  least  once  a  year  is  a 
precaution  which  should  be  taken  by  all. 

The  bacilli  of  glanders  will  remain  alive  under  natural  conditions  in 
stables  for  four  months;  hence  a  stable  in  which  a  glandered  animal  has 
discharged  virus  will  retain  its  infectiousness  for  a  long  time  after 
the  animal  has  been  removed,  provided  it  has  not  been  disinfected. 
There  are  many  other  contagious  diseases  of  animals  which  necessitate 
thorough  measures  of  disinfection  in  order  to  make  eradication  certain. 

In  view  of  the  importance  of  disinfection  in  preventing  the  spread  of 
disease,  the  following  directions  are  recommended  for  use  in  combating 
infections : 

1.  Permit  the  Entrance  of  a  Plentiful  Amount  of  Light.— The  bacteria 
of  tuberculosis  and  most  other  disease-producing  germs  are  destroyed 
by  the  direct  rays  of  the  sun  within  a  short  time.  They  are  destroyed 


by  less  intense  light  more  slowly,  and  will  live  for  long  periods  in  dark 
places.  There  are  numerous  other  advantages  in  having  plenty  of 
light  in  a  stable  that  are  not  necessary  to  mention  here. 

2.  Clean  the  Stable  Thoroughly.— Cleanliness  is  an  important  adjunct 
to  the  work  of  disinfection.  The  cleaning  of  the  stable  includes: 
(a)  removal  of  manure;  (b)  removal  of  piles  of  fodder;  (c)  removal 
of  rotten  woodwork  and  loose  boards,  especially  of  the  floor;  (d)  sprink- 
ling with  a  disinfectant,  to  lay  the  dust,  and  sweeping  of  the  ceilings, 
walls,  and  floor;  (e)  removal  of  dried  accumulations  about  mangers, 
floors,  and  drains.  The  practice  of  washing  the  floors  and  ceilings  with 
water  before  applying  the  disinfectant  has,  in  most  instances,  the 
disadvantage  that  the  water  carries  the  micro-organisms  to  be  destroyed 
into  cracks  where  they  will  not  be  affected  by  the  later  application  of 
the  disinfecting  solution. 

3.  Apply  Chemical  Disinfectants.— After  the  stable  has  been  treated 
as  recommended  above,  it  is  ready  for  the  application  of  chemical  dis- 
infectants. These  are  substances  which  poison  the  germs.  There  are 
many  of  them.  Some  are  far  more  efficient  than  others.  Among  the 
most  active  are  carbolic  acid  and  corrosive  sublimate. 

Carbolic  acid,  when  pure,  is  crystalline.  It  readily  assumes  the  liquid 
state  in  the  presence  of  a  little  water.  As  usually  dispensed  it  con- 
sists of  95  parts  of  pure  acid  and  5  parts  of  water.  For  use  as  a  stable 
disinfectant  this  should  be  mixed  with  water  in  the  proportion  of  one 
to  twenty,  or  one  pint  of  acid  to  two  and  one-half  gallons  of  water. 
The  "crude  carbolic  acid,  saturated  solution"  is  much  weaker  than  the 
above,  and  should  not  be  diluted  with  water. 

Bichloride  of  wsrcury,  or  corrosive  sublimate,  is  a  most  active  germi- 
cide, and  has  the  advantage  over  carbolic  acid  for  use  in  a  dairy  stable, 
in  being  odorless.  This  substance  is  poisonous  and  must  be  used  with 
great  care.  Before  it  is  applied  it  must  be  dissolved  in  water,  in  the 
proportion  of  one  part  to  one  thousand.  One  ounce  of  corrosive  sub- 
limate dissolved  in  eight  gallons  of  water  makes  a  solution  of  the  right 
strength.  In  making  the  solution  the  corrosive  sublimate  should  be 
dissolved  in  one  gallon  of  hot  water  and  then  mixed  with  enough  cold 
water  to  make  eight  gallons.  It  corrodes  metal,  hence  the  solution 
should  be  kept  in  a  wooden  tub  or  earthenware  crock. 

There  are  many  other  efficient  disinfectants,  but  the  two  above  de- 
scribed are  cheap  and  obtainable  at  any  drug-store.  In  the  employment 
of  commercial  disinfectants,  it  is  necessary  also  to  know  the  destructive 
value  of  the  solutions  for  the  organisms  to  be  destroyed.  There  are 
many  so-called  disinfectants  that,  in  the  strength  of  the  solutions 
recommended,  are  inefficient. 


3>y 


—  3  — 

Disinfectants  can  not  destroy  germs  with  which  they  do  not  conn  in 
contact.  The  disinfectant  should  be  applied  in  sufficient  quantity  to 
thoroughly  saturate  the  surfaces,  including  the  adhering  particles  of 
dirt.  In  the  application  of  the  disinfectant  it  is  well  to  use  a  broom 
and  thoroughly  scrub  the  floor  and  lower  parts  of  the  walls.  The 
solution  can  be  applied  to  the  ceilings  and  upper  parts  of  the  side  walls 
with  a  spray  pump,  and  must  be  carried  into  every  crevice  and  recess 
into  which  dirt  can  enter. 

After  disinfecting,  whitewash  the  stable.  Although  whitewash  is  not 
an  active  disinfectant,  in  the  usual  meaning  of  the  term,  it  is  an 
excellent  purifier  and  should  in  all  cases  be  used  in  stables  after  they 
have  been  thoroughly  cleansed  and  disinfected  with  other  agents.  If 
chlorid  of  lime  is  added  to  whitewash  in  the  proportion  of  one  pound 
to  three  gallons,  the  value  of  this  application  is  greatly  increased.  It 
is  advisable  to  whitewash  cow  stables  frequently,  at  least  once  in  six 
months,  and  better  every  three  months.  Hot  whitewash  for  this  purpose 
is  better  than  cold. 

In  preparing  the  above  directions,  abstracts  have  been  freely  made 
from  Pennsylvania  Circular  No.  2,  by  Dr.  Leonard  Pearson,  and  from 
"The  Pathology  of  Infectious  Diseases  of  Animals,"  by  Dr.  V.  A.  Moore. 


